Physical Sciences, Inc. (PSI), in collaboration with MD Anderson Cancer Center, will develop and test a novel technology for real-time assessment of tumor cellularity during core needle biopsy procedures. This technology will address one of the main issues that physicians encounter when performing biopsies: inability of collecting sufficient or adequate material for histological analysis due to tumor heterogeneity (mixture of viable tumor, necrosis, fibrosis and inflammation). As a result, biopsy success ranges from 70 to 95%, depending on the physician skills, tumor size, and biopsy location. Unfortunately, even when guided by ultrasound or CT, tumor cellularity remains an issue due to lack of resolution of these imagining modalities which cannot distinguish with certainty what areas of a mass contain viable tumor tissue. To address this problem PSI will aid the biopsy process by providing real-time tumor cellularity data captured by an optical biosensor which will investigate the morphology and the biochemical signature of the investigated mass, such that high tumor content regions can be reliably detected. The technology will be first tested ex vivo on tissue specimens and then its suitability for in vivo use will be tested on an animal model of cancer.